Chem Chem Flashcards
(45 cards)
What is an element?
any material that is made up of only one type of atom
what is a atom?
the smallest particle of an element that has all of the elements chemical properties
What particles are atoms made of?
electrons, protons, and neutrons
What is the atomic number?
the number of protons in the nucleus of an atom. (upper left hand corner)
atomic number = protons
protons= number of electrons
What is the atomic mass?
the total number of protons and neutrons. atomic number- atomic mass(# below element)= neutrons .
What is an isotope?
its when an element has equal numbers of protons but different numbers neutrons in their nuclei. (normally a radioactive form of an element)
What is a period and what is a group on the periodic table?
what is the trend for atomic size on the periodic table?
period- a horizontal row
group- a vertical column
- going horizontal, decrease in size, going down/vertical increase in size
What is an inner transition metal?
one of a group of chemical elements on the periodic table. They include elements 58-71 (lanthanides) and 90-103 (actinides). lanthanides are similar and actinides are radioactive.
What is radioactivity?
the process whereby unstable atomic nuclei break down and emit radiation
What is a alpha ray?
alpha- carry a positive electrical charge. combo of 2 protons and 2 neutrons. its large so its hard to go through things but it can damage the surface of things.
what is a beta ray?
carry a negative charge, originate inside the nucleus. able to penetrate paper or clothing and fairly deeply into skin
what is a gamma ray?
carry no charge. are the high frequency electromagnetic radiation emitted by radioactive elements. can penetrate most materials.
What is a nucleon?
What is the strong nuclear force?
- a collective name for protons and neutrons.
- a force that holds quarks together in elementary particles. it is the strongest force known in nature.
How do you find alpha decay?
you use 4/2 He.
example:
226/88 Ra becomes=
222/86 Rn… you subtract 4 on the top and subtract 2 on the bottom
How do you find beta decay?
you use o/-1 e
example:
3/1H becomes
3/2 He… the top stays the same and the bottom you add one
What is nuclear fission?
either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts. The fission process often produces free neutrons and gamma photons, and releases a very large amount of energy.
-used for atomic bombs
What does E=mc2 mean?
E= energy that any mass has at rest m= mass c= speed of light c2= proportionally constant of energy and mass
Where does nuclear fusion occur?
extremely high temps found in the sun and other stars.
- used for hydrogen bombs
- more powerful
- 2 light nuclei combine to form a heavy nucleus
what is matter?
physical substance that occupies space and possesses rest mass
what is a pure substance?
a substance that consists of only a single element or a single compound (element and compound)
What is a element?
any material that is made up of only one type of atom–pure
examples: gold, sulfur, nitrogen
what is a compound?
a material in which atoms of different elements are bonded to one another.
examples- salt, carbon dioxide, ammonia
what is a homogenous mixture?
a mixture in which the components are so finely mixed that the composition is the same through out–impure
what is a heterogenous mixture?
a mixture in which the various components can be seen as individual substances–impure